About Hip Replacement

After Hip Surgery

Recovering from Hip Surgery

What happens after hip surgery? Here are answers to commonly asked questions.

What can I expect during the hospital stay?

You can expect to see several people who will help with your recovery. A physical therapist will assist with hip exercises and walking. An occupational therapist will assist you with learning everyday activities, such as dressing and bathing, while your hip is healing. Your surgeon, his associates, medical doctors, and nursing staff will see you daily. A nursing assistant will help with bathing and activities that you are unable to do yourself.

The first night or two may be hard considering that you will have an unfamiliar bed, diet, and medications. Ask for a sleeping pill or anti-anxiety medication if that will help. Anticipate several weeks before your normal sleeping, eating, and resting patterns are restored.

How long will I stay in the hospital?

The average hospital stay after hip replacement is one or two days. The day after your surgery, you will be helped into a chair and you may be able to walk limited distances. Your activity will increase with each day that follows.

Recovery time varies from one patient to another. Much depends on other existing medical conditions. For example, arthritic disease in other major joints, heart disease, diabetes, obesity, depression, and other related conditions will affect recovery.

Most people return to their own place of residence after a hip replacement. Some elderly or debilitated patients may need to go to a nursing home to recuperate.

Preventing blood clots

What measures are taken to reduce the risk of blood clots?

For routine hip surgery, it’s common to use a blood-thinning medicine for about 4 weeks after surgery. In addition to a blood thinner, doctors also use early mobility, spinal anesthesia, leg exercises, foot pumps, and efficient surgery as adjunctive measures to minimize the risk of blood clots.

Why is a blood thinner needed after surgery?

This is to reduce the risk of a blood clot. Hip surgery is associated with a risk of blood clots developing in the calf, thigh, or pelvic veins. These clots often do not have any obvious symptoms or signs. Clots can cause chronic swelling of the legs, pain, and circulation and skin problems. In rare instances, a clot can break off and travel to the lungs, which can sometimes be fatal. This is why blood clots and blood-thinning medications are taken so seriously.

The risk of clots greatly decreases when the blood is thinned after surgery. Therefore, we use a blood thinner in every patient following hip surgery.

If you have ever had a blood clot before, or have ever had an adverse reaction to a blood thinner, please let your physician know so that he or she can plan an accordingly.

Common sensations

What sensations can I expect right after surgery?

Typically, patients have little to no pain, but nausea is more common. This nausea can come from the anesthetic drugs or from pain medicines and we can help control it by changing pain medicines and prescribing anti-nausea agents if necessary. If you have pain, nausea, or any other disagreeable sensation, let the nursing staff know. They are very knowledgeable in controlling such symptoms. Usually, an adjustment of medications is all that it takes to address any disagreeable sensations.

Why do I have a popping sensation in the new hip?

This can happen from a tendon, called the psoas tendon, rubbing against the new hip. With exercise and time, this sensation will disappear, assuming that it ever manifests in the first place. Usually this popping sensation occurs while the hip is healing, and while turning the leg side to side.

Why is the outside of my thigh numb?

This is normal after most anterior approaches to hip replacement or hip resurfacing. The incision cuts small nerve fibers that run from inside to outside of the hip, so the skin to the outside of the cut always feels numb after hip surgery. Usually, this sensation will resolve over time and is not a major problem for patients. Most patients will not notice that the outside of the scar feels numb.

Is it normal for the muscles to spasm and tighten after surgery?

Yes. Sometimes unexpected spasms of the leg muscles occur after surgery, usually as the person is healing from the operation. These spasms will go away. If they are particularly troublesome, your doctor can prescribe a muscle relaxant medicine, which can help.

Why are my appetite, mood, food-taste, and sleep different after surgery?

Altered appetite, bowel habits, depression, and mood swings are common after hip replacement. This is very important to know, understand, and anticipate. In some cases, medications might be necessary to control such symptoms.

All surgery elicits powerful psycho-social and physiological responses, which vary from one person to another. These responses are normal,; your medical team will help you get through them. It takes time for the body, mind, and soul to recover from any invasive operation.

Caring for your incision

Should I keep the incision covered?

Yes. Covering daily with a gauze dressing is best. You can shower with the dressing on, protecting it as much as possible, and then changing with a new dressing after the daily shower. Avoid touching the incision; the skin around the scar should be kept clean with soap and water. No antibiotic ointments are necessary.

Alternatively, you can remove the dressing, wash around the incision with soap and water, pat dry, and cover with a new dressing. Showering is safe at any time after surgery, but immersing the incision in a bathtub should wait until the stitches/staples are removed.

Can I put any lotion on the scar?

While stitches or staples are still in, avoid applying anything to the incision; simply keep it clean and dry. Once stitches or staples are out, you can use Vitamin E cream to massage and loosen the scar. Massaging the thigh area with an anti-inflammatory or cortisone cream can reduce skin inflammation and tenderness; many such ointments are available over the counter.

What if I am allergic to the adhesive used in the dressing?

If your skin cannot handle the adhesive or tape, or if there is drainage from the incision, a useful tip is to use feminine hygiene pads as a dressing. These are self-adhesive, comfortable, very gentle on the skin, and very absorbent.

Who will remove stitches and when?

Usually the home health nurse will remove stitches or staples, no earlier than 21 days after surgery. In some cases, the stitches may be left in longer, depending on the rate of healing. Home health nurses should take a digital photo of the incision if there is a concern and send it to your physician via e-mail.

When can I shower, take a bath, or swim?

Shower anytime after the surgery, if you can sit or stand safely with help. The incision can be covered with a plastic wrap. A new, dry dressing should be used to cover the incision after the shower.

Tub baths and immersion into water, such as a swimming pool, should be delayed until the stitches or staples are out and the skin has sealed completely. This takes at least a couple of weeks after surgery.

Swelling

How long will I have swelling and warmth in the surgical site?

Swelling and warmth around the scar are common after a hip replacement or hip resurfacing operation. The ankle may also swell on the operated leg. This represents the normal process of healing and can last for several weeks to months, depending on factors such as circulation, body weight, diabetes, and other variables.

Obesity, diabetes, poor circulation, poor muscles, varicose veins, high activity, heart disease, and swelling before surgery will usually result in a longer period of swelling and heat in the operated leg. Elevating your leg at night and wearing compression stockings during the day will help.

Deep aches and swelling in the hip can persist for a long time because bone, a living tissue, continues to re-model and adapt around the metal implants. This increased metabolic activity can lead to lingering soreness and swelling after heavy activity, all of which will disappear with time.

When can I stop wearing the compression stockings after hip replacement?

Compression stockings may be applied to both legs after surgery to control swelling, and many patients inquire when these can be discontinued. The answer is that if swelling is not a concern, you can stop wearing the stockings at any time.

These stockings are prescribed to control one of the most common nuisances after any hip operation, namely, swelling in the leg and ankle. The stockings have nothing to do with preventing blood clots; for that problem, it’s common to use a blood thinner and other strategies discussed here.

Preventing infection

How do you prevent infections during hip replacement?

Some of the key factors in reducing the risk of infection involve scrubbing of the skin with an antiseptic, antibiotics given before surgery, surgeon experience, a team-approach designed to promote efficiency, and standardized protocols. It is impossible to completely eliminate this risk, but it’s possible to get the risk down to nearly zero. It is very rare to have an infection after routine hip replacement. .

Is there a long-term risk of infection in an artificial hip?

Yes, there is a lifetime risk of infection with any artificial implant in your body, whether a hip joint, heart valve, or other synthetic component. As long as you maintain good health and appropriate body weight, avoid smoking, maintain proper hygiene, keep diabetes under control, and promptly address even minor infections in your body, the risk of infecting an otherwise well-functioning hip implant is essentially zero.

What if an infection does develop?

An early infection shows up as redness and pain around the healing incision. This can generally be treated with oral antibiotics alone, usually taken for 5 to 10 days. Very rarely, the hip joint has to be opened and washed out to clean the tissues and effectively treat an early infection.

A late infection that happens months or years after surgery is more serious, and will require additional surgery. Such infections occur because the immune system can be weakened by age, infirmity, tobacco use, heavy alcohol use, cancer, and other conditions.

In these cases, the infected prosthesis is removed and a temporary antibiotic-loaded hip is implanted. After three or more months, a new hip joint is implanted. Six weeks of antibiotics and these two operations will effectively treat an established deep infection in the hip. Fortunately, such cases are very rare, and late deep infections usually occur in immune-compromised patients with other serious medical problems.

Leaving the hospital

How will I manage at home?

If help from an adult family member or friend is not possible, it may be necessary to stay at an inpatient rehabilitation facility. You will not be able to drive for the first couple of weeks after surgery. If you go home, a home health agency will check on you at home, about three times a week or more, to help with walking, exercise, incision checks, medications, and communication with the doctor.

The home health agency will send a nurse to do blood draws and follow-up care, a physical therapist to continue therapy, and possibly an occupational therapist. The nurse also communicates with your physician to keep them updated on your progress.

How is my hospital discharge handled?

Typically, a social worker will visit with you after surgery and work with the therapists and nurses to formulate a discharge plan. The social worker will assist in coordinating discharge to your home, a skilled nursing facility, in-patient rehabilitation facility, or nursing home.

What determines when I can go home after hip replacement?

You can go home when you can ambulate safely with a walker, go up and down stairs, and get to the bathroom. Typically, you will have had a bowel movement before discharge, and will be able to take a shower. Your doctor is the one making the ultimate decision about the safety and timing of your discharge. You will need someone to drive you home from the hospital.

When must I come back for a visit after hip surgery?

You will return for a visit about one month after surgery; call or e-mail if you have questions before that time. This guide and your home health nurse can be helpful resources. Long-distance patients may use email, sending digital photos of their incisions and digital X-rays; this works very well and saves time and travel expense.

When should seek medical help?

Contact your doctor if you have any of the following:

persistent drainage from your incision;
excessive redness around the incision;
increase in the incision pain;
increased leg swelling;
pain and swelling in the calf of the leg;
temperature above 101 degrees;
numbness or tingling down the back of the operative leg;
chest tightness;
new cough;
difficulty breathing;
or any related concern.

Your family doctor is a good resource if you develop a cold, flu, nausea, vomiting, diarrhea, or constipation. If you are unsure, please contact your surgeon. If unable to reach a doctor, and you feel there is a problem, please go to the local emergency room.

Getting moving

Can I place full weight on the operated leg after surgery?

Yes. But, use some form of assistive device for at least a month after surgery, to avoid a sudden twist and fall. Hip implants are loaded in torsion (a rotational stress is placed on the implant each time you get up, turn in bed, or go up or down stairs), as well as loaded in compression (your weight pressing down). Putting full weight on your hip right after surgery is never a problem.

About a month after surgery, if you feel confident and balanced, you can walk without a cane, but if there is any question, stay with a cane until you feel safe.

In complex, repeat hip implant surgery, these instructions will be more specific to each unique situation. In almost all cases, however, at 12 weeks after such surgery, patients can resume all activities.

Can I kneel down after hip replacement surgery?

Yes. As soon as you’re comfortable, kneeling is safe, as is crossing our legs and lifting weights by bending the knees or back. It is not possible to damage the implants.

How soon can I drive after surgery?

With a left hip replacement, an automatic transmission, and a healthy right leg, you can drive any time after surgery that you are comfortable. Typically this time is about two weeks from surgery, but sometimes longer.

If the right leg is operated on, you can drive in 3 to 4 weeks after surgery. If you feel sleepy or sedated because of pain medications, then you should avoid driving until you are alert and can concentrate on driving.

How much therapy will I need?

You need approximately four weeks of therapy, usually at home, with a visiting home health nurse. Some patients need therapy after this four-week period, and others are already independent. If you need outpatient therapy, usually 4 to 6 weeks will suffice. Once you learn basic hip exercises, you will be able to do them at home.

How much movement can I expect in the new hip?

The amount of movement you achieve should be close to that of a normal hip. That said, existing scar tissue, contractures of the hip joint, severity of arthritis, pain tolerance, motivation for exercise, body size, and other variables profoundly affect how much mobility a person will get. For most patients, the amount of hip movement gained after replacement allows them to engage in all activities of daily life.

Should I exercise after hip replacement?

Yes. A regular program of light aerobic exercise is beneficial from many standpoints, and will optimize the outcome of your hip replacement. After your six- week post-operative appointment, recommended exercises include walking, swimming, golf, hiking, treadmill walking, stair climbers, light aerobics, weight training, and elliptical exercise equipment.

How active can a person be after a total hip replacement?

You can be as active as you want, and lift as much weight as you desire. Heavy impact exercises, such as basketball, football, soccer, and tennis are probably best avoided, since they contribute to increased prosthesis wear. Low-impact aerobics, bicycling, treadmills, swimming, and similar exercises are fine. Climbing, hiking, and other outdoor activities can be performed as tolerated.

Strength and endurance will build up over time. Modern total hip implants are very durable and designed to take repetitive impact loading for many decades, even in active and heavy patients.

When can I ride a lawn mower, tractor, horse, bicycle, or ATV?

Defer these things for one month after hip implant surgery. You may feel like you can handle such activities sooner, but there is no point in rushing things.

When can I go back to work after surgery?

It depends on the type of work. If you are in hard labor, it is best to wait for three months before swinging into full action. Prior to that time, you can return to some light duty work if this is possible.

For jobs that require some standing, sitting, and walking, it is possible to return earlier. It really depends a lot on the individual and the job. Typically, most people will give themselves at least 3 to 4 weeks after joint replacement before returning to work in some capacity, but some people have returned to work after just two weeks.

When can I drink alcohol after surgery?

Moderate, social alcohol use can be resumed anytime that you wish. Avoid alcohol while you are on any blood thinner or pain medication.

When can one resume sex after a hip replacement or resurfacing?

You can resume sex as soon as comfortable, and in any position that does not cause discomfort. With earlier hip replacement methods, certain restrictions and precautions applied, but these do not apply to modern hip replacements.

How soon can I travel?

As soon as you are comfortable with sitting down, you can travel by airplane or car; there is no specific time period. If you travel, be sure to exercise your calf muscles and ankles frequently. Also, get out of the car or walk the aisle of the airplane frequently to avoid the possibility of blood clots. Continue taking blood thinners while you travel during the first month after surgery.

How long does it take to feel normal after a hip replacement?

A great deal of the recovery takes place in the first two months, but complete return to normal takes longer. Bone around the metal parts keeps changing and remodeling for 1 to 2 years after surgery, which is why you can feel deep aches and can tell when the weather changes. After that time, the hip will feel normal.

Do you use a machine to move the hip after surgery?

No benefit has been shown from the use of continuous passive motion (CPM) machines in hip replacement. Some surgeons use such machines after knee replacement, but they are not needed following hip replacement.

How much can I lift after hip replacement?

You can lift as much weight as you can comfortably tolerate. Once tissues have healed, lifting, climbing ladders or stairs, getting up on roofs, and related activities are safe. Avoid these things for about three months after surgery, until we are sure that your bone has healed into the implants.

Mobility Tips

Tips on walking

The therapist will demonstrate proper and safe walking after a hip replacement, with the use of crutches or walker. The purpose of the walker or crutches is to avoid a fall or sudden twist. Weight-bearing is safe immediately after surgery. But until the implants have grown into the bone, a process that takes 4 to 6 weeks, a fall or other sudden twisting force on the leg can risk implant loosening or injury to the leg. Reflexes take time to return, and narcotic pain medications can further dull the senses. That is the reason for learning to use an assistive device as long as necessary after surgery.

The assistive device can be a walker, crutches, or a cane in either hand; as long as you feel confident and safe in balancing yourself and minimizing the risk of a fall. When using a walker, lean forward, and lead with either leg. When using crutches, avoid putting weight into the armpits; the proper technique is to load the arms as much as needed for a comfortable stride. When using a cane, the most bio-mechanical advantage comes from holding the cane on the side opposite the replaced hip.

Assistive devices can be discarded anywhere from 1 to 4 weeks after surgery, depending on a number of factors, such as narcotic use, return of strength, confidence in walking, return of reflexes, and patient preference. Patients recover differently from each other, and there is no harm in using an assistive device to help in walking for a longer or shorter duration. Because the hip replacement components are designed to heal directly to bone without use of bone cement, the skeletal stability of the implants is assured by 4 to 6 weeks, at the minimum. Around that time, the assistive devices can be discarded, in favor of normal walking in nearly all cases

Tips on stairs

The ability to go up and down stairs requires strength and flexibility. At first, you will need a handrail for support and will be able to go only one step at a time. Always lead up the stairs with your good knee and down the stairs with your operated knee. Remember, “up with the good and down with the bad.” In other words, going up stairs, lead with the good (non-surgery) leg, and coming down stairs, put the bad (surgery) leg down first.

You may want to have someone help you until you have regained most of your strength and mobility. Stair climbing is an excellent strengthening and endurance activity.

Do not try to climb steps higher than the standard height (seven inches) and always use a handrail for balance. As you become stronger and more mobile, you can begin to climb stairs foot over foot.

Managing pain & discomfort

Should I apply ice or heat to the hip as it is healing?

After surgery, and for the first two weeks, ice is more effective in reducing swelling and pain. After complete healing of the skin has occurred, you can use a moist heat pack if it feels comfortable. Soaking in a hot tub at this point may also be helpful.

Whom should I call for pain pills?

Please call the doctor’s office for pain medicines. State regulations allow some medicines to be phoned in; others require a written prescription. Please plan ahead, since narcotic prescriptions on weekends or Friday afternoons can be difficult to call in, mail in, or otherwise get filled.

How long can I have pain medications refilled?

Most patients will taper off the use of narcotic pain medications very quickly. Be aware that some narcotics cannot be phoned into pharmacies. If you will need refills over a weekend or holiday, be sure to contact medical staff during regular office hours.

Some patients require pain medications for a longer time, while others do not need them at all. Your physician will individualize treatment for every person.

How long should I take pain pills?

Most patients use pain medication for anywhere from 1 to 3 months. After three months, you should taper off and begin anti-inflammatory medicines and other non-addictive medicines for pain.

When taken over a long period of time, narcotic drugs create a tolerance that makes them less effective. That is why it is preferable to taper off narcotic drugs quickly after surgery, unless there are compelling reasons to continue use.

What if I need narcotics three months after surgery or if I have been taking them before surgery?

In such cases, the doctor who was filling the prescriptions prior to surgery may resume dispensing the medication. Very rarely, referral to a pain specialist is necessary for patients who are dependent on long-term narcotics.

If you were taking narcotics regularly before surgery, pain control is usually more difficult and complicated since the body is desensitized to the pain control medicines we use after surgery. In such cases, let your doctor know what you are taking before surgery so that they can adjust pain medicines accordingly.

Life with an artificial hip

How long will the artificial hip last?

In most cases, the hip replacement should outlast your lifespan. The 15-to-20-year data on the longevity of hip replacement components is excellent, with more than 90 percent of the implants still functioning well in many studies. But, this is neither a guarantee nor assurance, for the simple reason that life is unpredictable.

Many factors affect the future of a hip replacement or resurfacing, such as accidents, fractures, late infections, and deterioration in your overall health. How well you take care of yourself down the road is something the surgeon cannot control.

The longevity of a hip replacement thus depends on many factors, including the following:

Surgeon skill in implanting the components
Known history or track record of the implants
How well you take care of yourself and your health
Understanding and respecting the limitations of a prosthetic lifestyle
Your activity level and body weight
Avoiding high-impact or extreme sports

How do I know if I have a metal allergy to the hip part?

Orthopaedic implants are made of alloys of cobalt-chrome and titanium that have been implanted in millions of patients over the past several decades. Most instances of a persistently painful hip after replacement have to do with a problem related to the surgery, or possibly an infection. A true metal allergy is extremely rare, and seldom encountered in clinical medicine.

What will weather changes feel like in the hip?

Some patients report increased pain and stiffness, or can feel changes in the weather after hip surgery. These sensations are not common though, and usually will disappear over 1 to 2 years after surgery. For the first couple years, the bone adapts and grows around the metal prosthesis, and this bone activity probably leads to sensitivity to weather and pressure changes.

How about future dental work and other surgery?

Because you have an artificial hip joint in place, you must take care to protect it from infection. The same applies to any artificial implant in your body. Before having dental work (teeth cleaning, fillings, extraction or root canals) or certain medical procedures (colonoscopy, biopsy, endoscopies, etc.), you must take an antibiotic.

The antibiotic will help prevent bacteria from getting into the blood stream and thus into your hip. The odds of this happening are very rare, but the antibiotic can reduce this already small risk.

For routine dental prophylaxis following hip replacement surgery, antibiotics are recommended for your lifetime after the surgery.

In what other situations will I need antibiotics after the hip replacement?

Antibiotics given for other medical procedures may vary. Contact your medical professional for advice if there is any doubt. Antibiotics are needed if you develop an infection such as an abscessed tooth, pneumonia, bronchitis, and skin or urinary infections.

If you have a cut anywhere that develops an infection, conditions like a tooth abscess or ingrown toenail developing, seek medical attention urgently. Ignoring a festering sore means that there is a risk the bacteria could migrate to the hip, resulting in a serious deep infection, even though it happens rarely.

Will the new hip set off a metal detector at the airport?

Most likely, it will. Tell airport personnel that you have an artificial joint prior to entering the metal detector. Metal detection sensitivity at airports is highly variable, and it is impossible to say if a certain detector will set off the equipment. You will be given an implant identification card that you can carry to prove that you have metal hip replacement parts.

Can I have a MRI scan after hip replacement?

Yes. MRI scans of other parts of your body are safe after hip replacement. Although some old MRI scanning equipment may not be compatible with your prosthesis, the majority of MRI scanning equipment today is safe and compatible with hip replacement parts. You may also have a CT scan of any part of your body after a hip replacement.

How will I know if my hip implants are recalled?

In the extremely unlikely event of a recalled implant, you will be contacted by the company who made the device. All implants have lot numbers registered with the implant maker. This information is kept in your medical record. If you want a copy of your X-ray or exact implant type and model for your records, please let your doctor know.

Rest assured that of the millions of artificial joints implanted each year, the incidence of recall is exceedingly rare. Implant companies monitor the performance of their products very carefully.

Is there a long-term risk of failure of hip implants?

Implants are engineered to withstand your body weight and activity level, but the moving parts of a hip replacement do wear over a period of several decades. A properly aligned hip replacement done by a competent, experienced surgeon will usually last the lifetime of most patients.

Subtle component mal-positioning and suboptimal orientation can however compromise the lifespan of the implant. This is why the skill and expertise with which the hip is implanted in your body is a critical determinant of durability.

Parts and Materials for Hip Replacement

How do the implants work in a hip replacement?

You have a natural socket (called the acetabulum) in the pelvis. The hip ball normally sits in this socket. By reaming away the damaged bone and cartilage, fresh bone is exposed, and a slightly oversized hemispherical socket made of a sturdy, inert titanium alloy is impacted into your bony socket. Usually this impaction does not require fixation with screws since the mechanical press-fit is snug enough. Into this titanium shell, a bearing surface of polyethylene, ceramic, or metal is then locked mechanically.

Next, the femur (thigh bone) is prepared by cutting off the arthritic femoral head (the ball of your hip joint). The cavity inside the femur bone is enlarged, and a slightly oversized femoral implant is securely impacted into the femur. The stem has a metal junction at its top end, designed to fit an artificial ball. This ball is made of a cobalt-chrome alloy, or ceramic, and matches the diameter of the bearing earlier fitted inside the artificial socket.

Once the ball is placed in the socket during surgery, the surgeon must adjust leg lengths, implant stability, muscle tension, and range of movement of the hip joint. This is where surgeon judgment and expertise are critical. The new artificial ball will rotate inside the synthetic shell just like a natural hip ball and socket would, except the artificial parts will not produce any pain.

What materials are used in a hip replacement or resurfacing?

The structural parts are made of titanium alloy. Structural means that the skeleton grows and bonds permanently to these parts. Alloy means that the metal is not pure titanium. It is a mixture of other metals to enhance the safety, performance, and avoid possible allergic reaction to any one metal.

Titanium alloys are used for this purpose because of durability, biocompatibility, several decades of experience, and the fact that titanium is less stiff than other metals and therefore better suited for skeletal reconstruction.

The bearings are mounted on the structural parts, using specially engineered tapers. Bearing surfaces in the hip are made of plastic, metal, or ceramic. The choice of bearing depends on the individual patient.

In engineering hip replacement components, the structural parts are optimized for their ability to bind to living bone and for long-term biocompatibility and durability, while the bearings are optimized for the lowest wear rates.

What do you do on the socket side of a hip replacement?

On the socket (pelvic) side of a hip replacement or resurfacing, a metal half-shell is fitted inside the patient’s own bony socket. Inside this shell, a locking mechanism fastens the bearing, which can be polyethylene, metal, or ceramic. Screws were once used to fix the socket to the pelvis bone, but with modern designs, screws are rarely necessary.

The bearing part can be changed even years down the road, without disturbing the metal cup that has grown into the pelvis.

What do you do on the femur side of a hip replacement?

On the femur (thigh bone) side, the inside cavity of the thighbone is enlarged, and a metal femoral stem is implanted in this cavity, where it will bind to the bone. On this stem, an artificial ball is attached using an engineering taper. The ball is made of either cobalt-chrome metal, or ceramic. The ball can be changed at any time in the future, if need be, without removing the stem from the femur.

What brand of hip implants do you use?

Brands such as Zimmer, OMNI, and Wright Medical Products have been popular in the past, but new ones are always being tested. Look for designs that have withstood the test of time, with excellent long-term results. Implant companies make several models and designs of implants, and the precise application depends on individual patient needs and anatomy.

The most common bearing surface used in hip replacements is a cobalt-chrome ball with a cross-linked polyethylene socket liner. This bearing is built upon decades of experience with standard (non cross-linked) polyethylene; the material offers more flexibility and options to make hip replacement safe and predictable.

If you have a strong preference for a certain type of joint prosthesis, or a certain type of material, discuss that with your surgeon.

There is very little difference between the implants offered by the major manufacturers. Be wary when companies pay doctors to promote or use any product.

What if I want a particular brand of hip replacement?

Simply let your surgeon know. You want to work with someone who embraces the latest technology, biomaterials, and surgical methods.

Be cautious about the unregulated marketing and promotion of hip and knee implants though. Orthopaedic companies and hospitals want business, and their advertisements rarely give the complete picture. Your surgeon should offer you unbiased opinion about different implants, while respecting whatever decision you make in this regard.

How much do the parts used in hip replacement weigh?

The parts weigh about 3 to 5 pounds. The bone removed during hip replacement weighs a little less. So, you may gain a few pounds of body weight as a result of hip replacement surgery. This is more than balanced by the fact that people tend to lose weight after surgery due to diminished appetite and the stress of an operation.

Why does an artificial hip wear?

Everything wears out over time. Artificial hip bearings are no exception. During everyday activity, our hips endure several million cycles a year. People who are athletic or walk more than usual will load their joints even more. Cyclic loading leads to wear, even though modern hip bearings are extremely wear-resistant. But, no bearing surface is completely wear-proof.

Realistically, for most patients, bearing wear in an artificial hip is not a practical concern. Assuming the surgery is done properly, most modern hip bearings will last longer than the patient’s lifespan.

Where do wear particles from the artificial hip go?

All hip bearings produce microscopic wear particles that collect in the soft tissue envelope around the artificial hip. This layer of tissue, called the hip capsule, forms around the prosthetic joint after surgery. Cells in this layer act like a “biological sink” by absorbing and storing the wear particles.

Some wear particles migrate into the body, and are spread by the circulating blood to remote organs such as the heart, liver, spleen, and lymph nodes. No study has shown any adverse impact of such wear particles from artificial hips that spread throughout the body, although this remains an area of investigation and research.

What is the advantage of ceramic bearings in hip replacement?

Ceramics are synthetic materials, used in industrial applications. When used in orthopaedic bearings, their wear rates are extremely low.

A disadvantage of ceramic bearings is that there are fewer options for the surgeon. This is related to engineering limitations. With future developments, ceramic bearing use may become more widespread. Today, for most patients, a cobalt-chrome ball and cross-linked polyethylene offers the best trade-offs between safety, longevity, flexibility, long-term wear, and sizing options.

Can ceramic parts be used in my hip replacement?

Yes, such as a ceramic ball and a plastic socket. Or we can use ceramics in both the ball and the socket. Either combination offers extreme wear resistance and durability.

Old-design ceramics were brittle, and the extreme hardness of ceramic materials limited their use in hip replacement. The newer ceramics are super tough alloys, especially engineered for the orthopaedic market. They are safer, and have excellent long-term outcomes, with almost zero wear.

Even newer ceramic materials made of silicon nitride are in development; silicon nitride offers even less wear, with extreme durability and strength.

When do you use cement to fix the hip components?

Cementing implants is reserved for the elderly and for cases in which the bone anatomy requires a cemented implant. The majority of hip replacements are done without bone cement.

In decades past, cement was used extensively to attach metal parts to bone. Cement is now rarely use cement in hip replacements thanks to developments in biomaterials and implant design.

How durable are cemented parts in hip replacement or resurfacing?

Data from hip replacements done many decades ago show that cemented total hip sockets usually loosened up after 10 to 15 years and that cemented femoral stems usually loosened up after 15 to 20 years. Today, cement is rarely used in hip replacements; in fact, if a previously cemented hip replacement has come loose, the parts used in repeat surgery are of a cementless design. Such components are designed to heal to native bone; this type of skeletal fixation has almost indefinite durability.

How do cementless hip implants attach to bone?

They attach by healing directly to bone. Metal surfaces are designed with a porous honeycomb metal structure, into which bone can grow. This biologic fixation is very strong and will not loosen over time.

While bone is growing into such parts, initial stability relies on a mechanical fit between metal and bone. This is achieved by physically impacting or hammering the parts into bone during surgery.

Once bone grows into the socket and femoral stem, the bond is permanent.

Can I get the same hip implant that a famous celebrity has?

Implant companies use celebrities to promote hip replacement, typically showing the youthful lifestyle and active involvement in skiing, golf, and other outdoor activities. Please view all marketing and promotional information with skepticism; such information is not always complete.

In reality, participation in sports such as golf and other activities is just as possible with one brand of hip components as the other. No brand in the market today is superior in terms of returning patients to activities faster or in giving patients an advantage in a specific sport, no matter which celebrity a company pays to tout its products.

Do I need a custom implant or instruments made from CT/MRI studies?

Hip components come in many sizes, configurations, models, and geometries. Off-shelf components give a precise fit in nearly all the patients. In some cases involving congenital abnormality, special-sized components can be ordered if necessary.

Technology keeps advancing, and in the future, custom-built hips that are designed precisely for one person to ensure perfect leg lengths, tissue tension, fit, and sizing will probably become a reality. Surgery advancements will probably mean that some patients may even be able to go home the day of surgery. These innovations reflect research and product development that professionals around the country are actively engaged in at the present time, to further improve on the already very successful operation of hip replacement.

Do you use human tissue or parts for hip replacement?

In routine total hip replacement, no such tissue is needed. Many years ago, we used allograft bone in some complicated cases to restore deficient bone. But with newer metal composites that can be shaped like bone, human tissue is no longer necessary for hip surgery.

In fact, metal augmentation techniques have advanced such that we can help patients who in the past were probably beyond help. The ability to rebuild hips that have had multiple operations previously, and to restore people to function, is a practical advantage of innovation and improvement in our health-care system.

Can patients develop an allergy to the artificial hip?

Such occurrences are exceedingly rare. Most commonly, what is often called an allergy is a missed, subtle infection. True metal allergies are usually well known to the patient ahead of time. In such unusual cases, it is possible to use components made of alternative metals, based on allergy testing, to which the patient is not sensitive.

Some patients did develop allergies and reactions to the metal-on-metal bearings; those designs have been recalled from the market.

Hip Surgery Techniques

How are hip surgeries performed?

Common approaches are covered here.

What is a surgical approach?

The anatomic pathway used to reach the bones of the hip joint is also referred to as the surgical approach. Each surgical approach is a different technique to gain access to the joint itself, and exposes the anatomy for a hip replacement or hip resurfacing.

The most common hip joint surgical approach used by U.S. surgeons is called the posterior (from the rear) approach. Patients who have had a posterior approach typically have a curved scar on the outside of the thigh with a top part of the scar curving into the buttock. This approach is very popular, easy to learn, predictable, and cuts through a limited amount of muscle and tendon, resulting in good recovery.

Even in the hands of very good surgeons, the posterior approach is associated with a small risk of the hip popping out after surgery. Newer techniques and implants have reduced this risk somewhat, but a small possibility of hip dislocation remains associated with the posterior approach.

Another common surgical approach to hip replacement is the lateral (from the side) approach. The lateral approach also involves a scar on the side of the thigh, but instead of being curved, the scar is usually a straight line. The advantage of this approach over the posterior approach described above is a lower risk of dislocation.

The lateral approach nearly eliminates the risk of dislocation, but the approach involves cutting through more muscle tissue on the way to the hip joint. As a result, patients will usually have a slight limp after surgery, which generally disappears 6 to 12 months following surgery.

Another popular approach is called the anterior (from the front) approach. This method is still new in the U.S., with more surgeons using it every year. Very few surgeons in the United States use this approach routinely for all hip replacements. This is a true muscle-sparing approach with a very quick recovery.

What are the advantages of the anterior approach?

One advantage of the anterior approach relates to easier and safer patient positioning for surgery. The patient is on the back, which is a more natural position than placing the patient on the side, which is required in the posterior and lateral approaches.

Another advantage is that leg length checks are easier when the patient is on his or her back. Both legs can be easily assessed relative to each other.

Finally, the anterior approach does not cut through any muscle. The muscles are separated along their natural planes, and the entire joint can be replaced through a much shorter incision, with true sparing of muscle.

Muscle-sparing is beneficial in another way. The risk of dislocation (the hip ball popping out of the socket unexpectedly) is nearly zero with the anterior approach. With other methods of hip replacement, patients must follow certain precautions for a lifetime.

For example, patients are usually advised to not bend too far, tie shoes, or cross the legs for fear of the hip popping out of socket. These precautions and worries do not apply to hips replaced using our anterior approach.

Around 2003, a “two-incision” hip surgical approach was developed by surgeons in Chicago as the first truly minimally invasive hip replacement. We adopted that technique, published our results in peer-reviewed literature, and refined the method to make it safe and predictable in our patients.

The present-day anterior approach is an evolution of that work; instead of two incisions, the anterior approach allows us to perform the entire hip replacement through one short skin incision placed toward the front of the thigh.

Patient recovery and function are better with the anterior approach, when compared to conventional techniques.

What are the disadvantages to the anterior approach?

This technique is still relatively new and not widely used in the United States, since it involves new learning and is difficult to master. Very few surgeons use it routinely in all patients, given the technical challenges in learning it and getting comfortable with the technique.

Another reason is that with the scar in the front there is the risk of skin numbness over the side and front of the thigh as the result of microscopic skin nerves that are cut in during surgery. These nerves will heal over time, and thigh sensation is restored a few months after surgery. The nerves do not affect any muscles; subjective numbness is the only symptom.

Thigh numbness is usually not a significant issue other than a transient symptom that resolves. It is generally agreed that the temporary numbness is more than balanced out by the substantially improved recovery, reduced pain, absence of a limp, faster return to function, and virtual elimination of the risk of hip dislocation.

What surgical approach is typical for a complex total hip replacement?

In very difficult hip reconstructions, such as those in which the hip has been replaced many times previously, or the pelvis has to be repaired with plates and screws before placing a metal socket, or where extensive repair of the femur needed, the surgical method that spares the muscles while permitting the best exposure is called a trochanteric osteotomy.

A trochanteric osteotomy involves cutting a piece of bone near the top of the femur. This bone is called the trochanter, and is the bump you can feel on the side of the thigh. The major hip muscles involved in walking all attach to the trochanter.

Cutting the trochanter with all the muscles still attached is the oldest of hip approaches. Once the trochanter is cut, it can be moved aside along with the attached muscles, thereby facilitating entry into the hip joint. The resulting view of the hip is excellent for any type of hip replacement, no matter how complicated or difficult.

Metal cables are used to reattach the trochanter to the femur. The trochanter can be attached farther down the femur if tightening of the muscles is desired. This method gives the surgeon the freedom and flexibility to adjust leg lengths and tissue tension, independent of each other.

For first-time hip replacements, and even many repeat hip replacements, a trochanteric osteotomy, despite its above advantages, is rarely needed. This method is dictated by complex, difficult, and unusual hip replacement cases.

Do surgeons use computer navigation during hip replacement surgery?

Precise alignment of the bones and components is essential to the long-term success of both hip replacement and hip resurfacing. Computer and robotic technology can help in alignment of bones and reduce the possibility of error.

However, so far there is no substitute for the skill, judgment, experience, hands, and eyes of a high-volume surgeon.

Future technology is aimed at building custom hip components for each patient, thereby ensuring a precise operation and optimal implant placement, with no need for robots or computers.

What is the role of computer guidance in hip replacement?

At present, computer-assisted technology is most effective for low-volume surgeons. It helps such surgeons reduce the likelihood of error in implantation of the hip components. For some surgeons and hospitals, the greatest advantage of this technology is in marketing.

In other words, computer and robotic technology, while sounding fancy, do not add much value to the hands of an experienced, high-volume surgeon.

What about that minimally invasive hip replacement that I read about?

Bear in mind that all surgery is invasive to the mind, body, and psyche. Surgery is a very different experience for the patient than it is the surgeon, hospital, or implant manufacturer. Hip surgery is much easier today when compared to the past, but complications, pain, discomfort, and recovery still apply. Each patient’s expectations and physical, emotional, personal, and spiritual attributes are different and affect recovery profoundly.

For example, some patients can leave the hospital the same day or the day after hip replacement. But this is not true of all patients. Unfortunately, some health-care professionals use words like minimally invasive surgery, computer-driven surgery, custom-built implants, and same-day operation as business-driving tools. This type of marketing can be misleading and can create unrealistic expectations.

How long will my scar be?

The scar is about 3 to 5 inches long, and placed in front of the thigh. The length of the scar can vary, and will depend upon patient body size, the severity of arthritis, the condition of the soft tissues, and the deformity of the joint.

While the length of the scar has little to do with how fast you heal, everyone prefers to have the shortest scar. Your surgeon will aim for the smallest possible incision that allows safe and efficient surgery, with accurate implant placement.

Independent of the scar length, hip replacement surgery with our anterior approach avoids muscle damage. By spreading muscles apart, the recovery is much faster and easier.

Are there newer surgical approaches being developed?

Yes, there are exciting innovations constantly being developed. One example is the “Super-PATH” technique with which we hope will improve recovery by minimizing surgery so much that same-day discharge may be possible for some patients. These efforts entail painstaking, detailed experimental work in the laboratory, extensive cadaver-surgery training, development of new instruments, and collaboration with experienced and gifted colleagues nationwide.

Types of Hip Surgery

What is hip resurfacing?

In hip resurfacing, a metal cap is glued on the arthritic ball instead of replacing the ball itself. Some implant companies and surgeons have promoted hip resurfacing in recent years, but hip resurfacing has been around for many decades.

How are hip resurfacing and hip replacement different?

Hip resurfacing and hip replacement are similar. Both replace all arthritic surfaces in the arthritic hip. On the socket side, both operations entail removing a layer of arthritic bone and cartilage from the pelvis, and replacing it with a metal cup.

The main difference between hip replacement and hip resurfacing is what is done to the femoral bone (thighbone).

In hip resurfacing, the arthritic ball is prepared such that a metal cap is glued onto your bone. The diameter of the metal cap matches that of the artificial socket.

In hip replacement, the arthritic femoral ball is cut and replaced with a new ball. The inside of the femur bone is prepared to implant a metal stem 3 to 5 inches in length. On this stem, a mechanism allows attachment of a metal or ceramic ball that matches the size of the socket. Once the ball is placed into the socket, the hip replacement is complete.

Do hip replacement and hip resurfacing cost the same?

A hip resurfacing is more expensive because surgical time is longer and the implants are more costly. At present, the parts for hip resurfacing cost about twice as much as hip replacement parts.

What are the advantages of hip resurfacing?

The advantage of hip resurfacing is preservation of 1 to 2 inches of bone, on top of the thighbone. In theory, if you need repeat surgery in the future, this bone is available to the surgeon to work with.

This made sense in previous decades, when the lifespan of hip replacements was limited by material quality; the older synthetic ball-socket would wear out in 10 to 15 years. The wear particles would result in inflammation and bone loss around the implants. As a result, the implants would loosen, requiring repeat surgery.

Modern hip replacement bearings and implants are much improved though, and should outlast the lifespan of most patients. This assumes of course that the prosthetic parts are properly implanted and accurately aligned during surgery.

Also, today, if repeat surgery is needed on a prosthetic hip, modern metal technologies allow us to rebuild and reconstitute missing skeletal bone.

Therefore, the only advantage of hip resurfacing (preservation of an insignificant amount of femoral bone) when compared to hip replacement, has little practical value.

Hip resurfacing and replacement feel the same to patients, and are equally effective in relieving pain, restoring function, and restoring the ability to participate in any activity.

What are the disadvantages of hip resurfacing?

One, the metal cap must be glued to the arthritic femoral head. This glue can loosen up over time, causing the resurfacing to fail. There is no cement-less version of the metal cap in hip resurfacing.

Two, the bone directly underneath the metal cap, called the femoral neck, can break, especially if it is weakened during implantation of the metal cap. If this happens, urgent surgery is needed to convert the hip resurfacing to a hip replacement.

Three, hip resurfacing is more invasive than hip replacement. Since the femoral head is preserved in hip resurfacing, the surgeon has less room to work; therefore, the incision is longer and the surgical exposure is more extensive with hip resurfacing. Some surgical methods, such as the anterior surgical approach, allow hip resurfacing through a less invasive approach, but the operation is still more extensive than a hip replacement.

Four, the only kind of bearing in hip resurfacing is metal-on-metal. In hip resurfacing, the inside of the socket is a polished metal, and so is the metal cap that covers the femoral head. Actual hip movement in hip resurfacing is from metal-metal contact; this bearing is the only one possible in all modern hip resurfacings. Recent studies have raised a worry that metal-metal hip bearings can cause a reaction in some patients, requiring more surgery.

What are the advantages of hip replacement?

A key advantage is its longevity and track record. The technology used in modern hip replacements is safe and well-proven in millions of patients. The nuances, complications, surgical techniques, and outcomes of this operation have been thoroughly investigated. A properly performed hip replacement should outlast the patient; this is significant since no one wants repeat surgery.

Of note, different bearing surfaces can be used in hip replacement. This is because there is more latitude in the engineering design of hip replacement components. In hip replacement, once the metal shell and the femoral stem are implanted, the surgeon and patient have a choice of bearing, including metal-metal, metal-plastic, metal-ceramic, ceramic-plastic, and ceramic-ceramic.

Also, hip replacement bearings can be changed out several years after the surgery; the bearings are removable independent of the implants. In contrast, hip resurfacing bearings cannot be changed; the entire component must be removed, along with some bone, if a change of bearing is desired for any reason in the future.

What are the disadvantages of hip replacement?

The disadvantage, when compared to hip resurfacing, is that an additional 1 to 2 inches of bone at the top of the femur must be sacrificed. However, removal of this bone is of little, if any, practical consequence. If a hip replacement should ever fail, repeat surgery is relatively straightforward and predictable in the hands of an experienced surgeon. Also, we have many ways of making up for lost bone today; saving an inch or two of bone is of no clinical consequence over the long-term.

What if I choose to have hip resurfacing based on what I have read?

If a hip resurfacing is your choice, then that is the operation your surgeon should perform for you. In our practice, there is no preference or bias, nor any financial inducement toward one procedure or the other. The above comments are presented to share information known to professionals in our field, and may differ from claims made by hospitals and surgeons promoting hip resurfacing.

Leg Length

Can hip replacement surgery change your height?

You’d be surprised how often this question is asked, and the answer may surprise you!

If both hips are replaced, can you add height to my body?

Yes. If both hips are replaced, it is possible to increase the leg length on one side and increase it by the same amount on the other side. But, any gain in height is about an inch or less. The limiting factor includes the muscles, tendons, and nerves, which only have so much stretch before there is injury or damage.

It is possible to replace both hips at the same time, if the patient is healthy enough for such surgery. Recovery from two hip replacements does not differ much from having one hip replaced, at least with newer, less-invasive surgical methods.

Will my leg be longer or shorter after hip replacement surgery?

This is an important topic, and should be understood before you embark on any hip replacement, no matter where you have the hip replacement done.

Hip resurfacing is an operation that is similar to replacement. During resurfacing, the arthritic ball is capped with metal, and an artificial socket is placed in the pelvis. Any bone removed is replaced with an equivalent thickness of metal in hip resurfacing, so there is no noticeable gain or loss in leg length during hip resurfacing.

In contrast to hip resurfacing, during hip replacement the arthritic ball is removed and replaced with a new ball. Since the artificial ball comes in different neck lengths, the surgeon is able to adjust muscle tension, leg length, and ball-socket stability during the hip replacement. These adjustments reflect complex decision-making and trade-offs during surgery. Rarely, because of anatomic constraints or other patient-specific reasons, slight leg lengthening may occur. If this is totally unacceptable, you should not consider hip replacement surgery.

In the overwhelming majority of cases, there is no change in leg length after hip replacement. In most cases where the patient feels a change in leg lengths, that perception will disappear over several months as the muscle and tissues stretch.

Can leg length be changed during hip replacement surgery?

Yes. An example would be a patient with a leg that was shortened from injuries after a motor vehicle accident, who now needs a new hip. In such cases, it is possible to restore the original leg length during surgery. The decision-making is complex, requires professional judgment, and is specific to each situation.

Likewise, if the patient has too long a leg before surgery, it is possible to shorten it during hip replacement, using specific surgical techniques that keep muscle tension within safe limits. Again, the exact steps taken and the decision-making are specific to each patient.

My leg ended up too long after a hip replacement. Can anything be done?

In most cases, with exercise, stretching, and healing over 6 to 12 months, the perception of a leg length difference will disappear on its own. During this time, to avoid a limp and facilitate walking, a shoe-lift built into the shoe can help.

The reason for waiting is that the majority of leg-length discrepancy after hip replacement is not a true difference in skeletal lengths. Rather, the discrepancy is from pelvic tilt, tight muscles, altered biomechanics, and even spinal arthritis that can lead to a curvature in the back. With muscles stretching, exercises, and time, such discrepancy will likely resolve in a few months.

If leg length discrepancy is permanent, additional surgery may be an option. During such surgery, the femoral stem component is removed, and the bone at the top of the femur is removed to equalize the leg lengths. Then, a new femoral stem is implanted.

While this sounds easy, additional steps must be taken to avoid improper muscle tensioning and to reduce the risk of creating hip instability and a limp. Recovery from this type of surgery is about 6 to 12 weeks.

How can we know if my leg is truly longer after a hip replacement?

Special X-ray studies can help determine if the perceived difference in leg lengths is really in the bone or arising from some other source, such as a tilted pelvis, a curvature in the back, or tight muscles. These X-rays, called scanograms, involve imaging the entire length of both legs with a measuring ruler that leaves no doubt about the actual length of each leg, from the top of the pelvis to the ankle.